1. Field of the Invention
This invention relates in general to portable or handheld medical diagnostic devices and, in particular, to a compact device having an adjustable adaptor for accommodating a variety of different heads. More specifically, but without restriction to the particular embodiment hereinafter shown and described, this invention relates to a compact device having a pair of instrument heads which are independently extendable and, once extended, smoothly turnable through 360 degrees in consecutive ninety degree increments.
2. Discussion of the Prior Art
The art of hand-held compact diagnostic devices has been contributed to by a number of proposed devices including, for example, the handle-case disclosed in U.S. Pat. No. 3,812,847 which issued to W. C. Moore et al. May 28, 1974. These devices are conveniently carried by doctors and practitioners periodically or throughout the entire work day, thus making them readily available when needed.
The Moore et al. device includes a pair of illuminated medical instrument heads which are each permanently secured to a corresponding base contained in the handle-case. When the case is opened, the base allows the instrument head to be folded out with a predetermined orientation. Once the instrument is folded out, it is positionable in any one of six possible orientations relative to the handle-case. The six orientations include the predetermined orientation which is required to fold the instrument into the case and properly close the cover thereover.
In other prior devices wherein the instrument head is releasable from the base, the predetermined orientation aligned for proper closure requires precise and costly machining to time the threads on the base to those provided in the neck of the instrument head so that when the instrument is tightly screwed to the base, the head obtains the desired predetermined orientation. It is only with this predetermined orientation that the cover may be properly closed against the case. Since the typical instrument head has an irregular shape, folding the instrument into the case with any other orientation would result in a portion of the instrument projecting out of the case thus interfering with the cover and preventing proper closure. The precise machining required to give the instrument head the desired orientation serves as an impediment to providing the device with optional instrument heads. This is true because of manufacturing difficulties encountered in providing a new instrument head having a different irregular shape with the exact timing of threads needed to give the instrument the desired predetermined orientation required for proper closing of the case cover.
Previously proposed compact diagnostic devices are thus limited in that they are either unable to accommodate any type of interchangeable head since the head is permanently attached to the base, as in the Moore et al. device discussed above, or require expensive and precise machining which hinders the option of providing a variety of different compatible heads. Such devices are further limited in restricting the number of possible orientations once the head is extended.